Cooperative Fish and Wildlife Research Units Program: Oregon
Education, Research and Technical Assistance for Managing Our Natural Resources

Objective 1: Describe the body morphology, including body size, of adult Pacific lamprey for the purpose of discerning sexual dimorphisms and stage of maturation. Objective 2: Estimate the fat content of Pacific lamprey for the purpose of discerning sexual dimorphisms and maturation characteristics. Objective 3: Identify the sex and status of reproductive maturation of adult Pacific lamprey through gonad histology and hormone assays. Objective 4: Identify potential links between the energetic status and reproductive development and the seasonal river flow and thermal regimes of adult Pacific lamprey collected at Willamette Falls and compare this information with lamprey recently returned from the sea (to be used as a baseline comparison) for the purposes of identifying runs of Pacific lamprey at Willamette Falls.